A debate continues to rage in the academy and on the U.S. Supreme Court about the propriety of originalism as a methodology of constitutional interpretation. In federalism cases both the majority and the dissent on the current Court appear to have embraced originalism, yet their agreement ends there: The Court has consistently divided 5–4 in such cases. What explains the disagreement among Justices who appear to agree that the original understanding of the Constitution is also its current meaning? This Article presents the results of a study of citation patterns in federalism cases since 1970 and demonstrates that the Court’s current majority in such cases gives substantially more weight than the dissent to Anti-Federalist views. To the extent that the majority relies on Federalist views in establishing the original understanding, it is substantially more likely than the dissent to cite Federalist statements that appear to have been made to allay Anti-Federalist fears about the power of the national government or that (at a minimum) demonstrate more solicitude for state autonomy. Conversely, the dissent is substantially more likely than the majority to cite as evidence of the original understanding the more unabashedly nationalistic views of Federalists; the majority rarely cites such statements as evidence of original meaning, choosing instead to discount them as outside the framing mainstream or to read them narrowly or in a context that renders them more federalistic in nature. The results of the study have implications for originalism. Although proponents of originalism have defended the approach on the ground that it constrains judges’ ability to impose their own views under the guise of constitutional interpretation, the study suggests that judges seeking the original understanding are largely unconstrained in their ability to mold the historical record to serve instrumentalist goals.